The USC-UCLA Drug-Induced Liver Injury Clinical Center (CC) application in response to RFA-DK-13-003 Continuation and Expansion of the Drug Induced Liver Injury Network (DILIN) hopes to continue to participate with the other CCs to advance the scientific knowledge and clinical evaluation of DILI. Our application will continue to combine the only two medical schools in Los Angeles County allowing us to continue to uniquely capture and enroll DILI cases into the Networks database supervised by the Data Coordinating Center (DCC). The 9.3 M residents of Los Angeles County (2011) are an unmatched resource composed of the most ethnically diverse population in the United States. Our application continues to utilize the expertise and talents from USC and UCLA medical centers. The enrollment of a large number of bona fide and ill patients with close follow up has demonstrated our CC's ability to capture DILIN cases in this diverse populations. The Specific Aims for the continuation of the USC-UCLA DILI CC are to: 1) Continue enrollment of high quality cases with collection of disease controls and acute cases for mechanistic studies; 2) Detailed analysis of cholestatic DILI due to HDS using genetic and serum analysis; 3) Immunological surveying of acute DILI cases compared with disease control to identify potential mechanism of liver injury; 4) Proteomic studies in acute cases of hepatocellular to identify mechanism of disease; and 5) Support of DILIN effort to develop assessment instruments and a treatment trial.